What is the importance of animals, microorganisms and fungi in biogeocenosis?

Biogeocenosis is an evolutionarily developed, spatially limited, long-term self-sustaining, homogeneous ecological system in which living organisms and the abiotic environment surrounding them are functionally interconnected. Living organisms are exactly what you listed in the title of your question. That is, without these living organisms there is and will not be any biocenosis. Consequently, the importance of animals, microorganisms and fungi in biogeocenosis is fundamental.